The present studies suggest that single-nucleotide polymorphisms and composite genotypes or haplotypes of the IL6 promoter may be associated with several features of the metabolic syndrome in Caucasians.
A tendency to increase the inflammatory markers IL-6 (p = 0.069) and MCP-1 (p = 0.067) was observed in those patients suffering from MS. An increase in the cardiovascular risk markers PAI-1 (p = 0.007) and triglycerides/HDL cholesterol ratio (p < 0.0001) was also found in the MS group.
Low COX4I1 was associated with type 2 diabetes in obese patients, adjusting for age, gender, smoking, interleukin-6 and high-sensitivity C-reactive protein, all related to metabolic syndrome (MetS; odds ratio: 6.1, 95% confidence interval: 2.3-16).
Circulating concentrations of adipokines (ie, tumor necrosis factor-alpha, adiponectin, resistin, leptin, and interleukin-6), markers of nitrosative stress (nitrotyrosine), dietary habits, and MTP -493G/T polymorphism were cross-sectionally related to the presence and severity of insulin resistance (homeostasis model assessment index for insulin resistance: >or=2), the metabolic syndrome, and fatty liver in 64 nonobese nondiabetic patients with NAFLD (33 insulin-sensitive and 31 insulin-resistant subjects) and 74 control subjects without liver disease who were matched for sex, BMI, homeostasis model assessment index for insulin resistance status, and the various features of the metabolic syndrome.
The significantly higher distribution of risk polymorphisms in PSEN1 and APOE-ε4 is characteristic of a representative number of patients with Alzheimer's disease; whereas polymorphisms in ACE, AGT(235), and IL6(573), are most probably related with the high number of patients with metabolic syndrome or cerebrovascular damage.
The upregulation of IFNγ and IL-6 and CRP suggests that autoinflammatory process may play a significant role in the pathogenesis of metabolic syndrome.
This study investigates whether IL-6 promoter variants -174 G/C and -573 G/C are associated with quantitative traits related to the metabolic syndrome (International Diabetes Federation criteria) in a population of normoglycemic subjects (n=878) from the latest KORA survey (KORA S4).
The pooled results using random effects model indicated that melatonin supplementation significantly reduced C-reactive protein (CRP) (SMD = - 1.80; 95% CI - 3.27, - 0.32; P = 0.01; I<sup>2</sup>: 95.2) and interleukin 6 (IL-6) concentrations (SMD = - 2.02; 95% CI - 3.57, - 0.47; P = 0.01; I<sup>2</sup>: 91.2) among patients with MetS and related disorders; however, it did not affect tumor necrosis factor-α (TNF-α) concentrations (SMD = - 1.87; 95% CI - 3.81, 0.07; P = 0.05; I<sup>2</sup>: 94.4).
In the logistic regression model adjusted for age and sex, higher IL-6 and lower IGF-1 levels confer increased risk of having MetS and its two underlying pathophysiological abnormalities, i.e., visceral obesity and insulin resistance.